@import url('https://fonts.googleapis.com/css2?family=Baloo+2:wght@500;700;800&family=Nunito:wght@400;600;700;800&display=swap');

:root {
  --bg: #F6F3EC;
  --bg-wash: #EFE9FB;
  --surface: #FFFFFF;
  --surface-2: #F3F1EA;
  --border: #E4E1D6;
  --text-primary: #2C2C2A;
  --text-secondary: #6B6A63;
  --text-muted: #9A988F;

  --purple: #7F77DD;
  --purple-bg: #EEEDFE;
  --purple-dark: #3C3489;
  --teal: #1D9E75;
  --teal-bg: #E1F5EE;
  --teal-dark: #085041;
  --coral: #D85A30;
  --coral-bg: #FAECE7;
  --coral-dark: #993C1D;
  --amber: #EF9F27;
  --amber-bg: #FAEEDA;
  --amber-dark: #854F0B;
  --red: #E24B4A;
  --red-bg: #FCEBEB;
  --red-dark: #791F1F;

  /* ---- liquid-glass tokens: translucent surfaces over a soft color-mesh
     background, so backdrop-filter has something worth blurring ---- */
  --glass-surface: rgba(255, 255, 255, 0.52);
  --glass-surface-strong: rgba(255, 255, 255, 0.74);
  --glass-border: rgba(255, 255, 255, 0.65);
  --glass-highlight: rgba(255, 255, 255, 0.85);
  --glass-shadow: 0 10px 30px rgba(40, 35, 70, 0.10), 0 1px 2px rgba(40,35,70,.05);
  --glass-blur: 24px;
  --mesh-1: rgba(127,119,221,.32);
  --mesh-2: rgba(29,158,117,.20);
  --mesh-3: rgba(216,90,48,.15);

  --radius: 16px;
  --radius-pill: 999px;
  --font-display: "Baloo 2", "Nunito", sans-serif;
  --font-body: "Nunito", -apple-system, "Segoe UI", sans-serif;
  color-scheme: light;
}

[data-theme="dark"] {
  --bg: #131318;
  --bg-wash: #201C33;
  --surface: #212024;
  --surface-2: #2A292E;
  --border: #3A393F;
  --text-primary: #F1EFE8;
  --text-secondary: #B4B2A9;
  --text-muted: #7E7D77;

  --purple-bg: #2A2560;
  --purple-dark: #AFA9EC;
  --teal-bg: #0B3A30;
  --teal-dark: #5DCAA5;
  --coral-bg: #4A2415;
  --coral-dark: #F0997B;
  --amber-bg: #4A3208;
  --amber-dark: #FAC775;
  --red-bg: #4A1414;
  --red-dark: #F09595;

  --glass-surface: rgba(42, 41, 48, 0.55);
  --glass-surface-strong: rgba(42, 41, 48, 0.78);
  --glass-border: rgba(255, 255, 255, 0.09);
  --glass-highlight: rgba(255, 255, 255, 0.12);
  --glass-shadow: 0 10px 30px rgba(0, 0, 0, 0.4), 0 1px 2px rgba(0,0,0,.3);
  --mesh-1: rgba(143, 135, 232, .28);
  --mesh-2: rgba(93, 202, 165, .16);
  --mesh-3: rgba(240, 153, 123, .12);
  color-scheme: dark;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #131318;
    --bg-wash: #201C33;
    --surface: #212024;
    --surface-2: #2A292E;
    --border: #3A393F;
    --text-primary: #F1EFE8;
    --text-secondary: #B4B2A9;
    --text-muted: #7E7D77;

    --purple-bg: #2A2560;
    --purple-dark: #AFA9EC;
    --teal-bg: #0B3A30;
    --teal-dark: #5DCAA5;
    --coral-bg: #4A2415;
    --coral-dark: #F0997B;
    --amber-bg: #4A3208;
    --amber-dark: #FAC775;
    --red-bg: #4A1414;
    --red-dark: #F09595;

    --glass-surface: rgba(42, 41, 48, 0.55);
    --glass-surface-strong: rgba(42, 41, 48, 0.78);
    --glass-border: rgba(255, 255, 255, 0.09);
    --glass-highlight: rgba(255, 255, 255, 0.12);
    --glass-shadow: 0 10px 30px rgba(0, 0, 0, 0.4), 0 1px 2px rgba(0,0,0,.3);
    --mesh-1: rgba(143, 135, 232, .28);
    --mesh-2: rgba(93, 202, 165, .16);
    --mesh-3: rgba(240, 153, 123, .12);
    color-scheme: dark;
  }
}

* { box-sizing: border-box; -webkit-tap-highlight-color: transparent; }

/* Kill the default focus ring on tap/click (that's the blue box) but keep
   one for keyboard navigation via :focus-visible, so accessibility doesn't
   just get thrown away along with the ugly default. */
button, a, input, select, textarea, [tabindex] {
  outline: none;
}
button:focus-visible, a:focus-visible, input:focus-visible,
select:focus-visible, textarea:focus-visible, [tabindex]:focus-visible {
  outline: 2px solid var(--purple);
  outline-offset: 2px;
}

body {
  margin: 0;
  font-family: var(--font-body);
  background:
    radial-gradient(900px 600px at 8% -8%, var(--mesh-1), transparent 60%),
    radial-gradient(800px 550px at 105% 4%, var(--mesh-2), transparent 55%),
    radial-gradient(750px 550px at 46% 108%, var(--mesh-3), transparent 60%),
    var(--bg);
  background-attachment: fixed;
  color: var(--text-primary);
  padding-bottom: 3rem;
  -webkit-font-smoothing: antialiased;
}

.wrap {
  max-width: 480px;
  margin: 0 auto;
  padding: 0 16px;
}

h1, h2, h3 { font-family: var(--font-display); font-weight: 700; }

/* ---- top bar ---- */
.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 0 8px;
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  font-family: var(--font-display);
  font-size: 15px;
  font-weight: 700;
  padding: 6px 14px 6px 6px;
  border-radius: var(--radius-pill);
}

.badge-streak { background: var(--coral-bg); color: var(--coral-dark); }
.badge-xp { background: var(--amber-bg); color: var(--amber-dark); }

/* ---- 3D bubble icons: radial gradient + glow + glossy inner highlight ---- */
.icon-3d {
  --c1: #fff; --c2: #ccc; --c3: #999; --glow: rgba(0,0,0,.4);
  width: 26px; height: 26px;
  border-radius: 50%;
  display: inline-flex; align-items: center; justify-content: center;
  position: relative; flex: none;
  background:
    radial-gradient(circle at 32% 28%, rgba(255,255,255,.85), rgba(255,255,255,0) 38%),
    radial-gradient(circle at 35% 30%, var(--c1), var(--c2) 55%, var(--c3) 100%);
  box-shadow: 0 0 9px 1px var(--glow), inset 0 -2px 3px rgba(0,0,0,.25);
}
.icon-3d svg { color: #fff; filter: drop-shadow(0 1px 1px rgba(0,0,0,.25)); }
.icon-3d.flame { --c1:#FF9E6E; --c2:#D85A30; --c3:#A83E1D; --glow: rgba(216,90,48,.55); }
.icon-3d.bolt  { --c1:#FFD98A; --c2:#EF9F27; --c3:#B4740F; --glow: rgba(239,159,39,.55); }
.icon-3d.purple{ --c1:#C3BDF5; --c2:#7F77DD; --c3:#544BB8; --glow: rgba(127,119,221,.5); }
.icon-3d.teal  { --c1:#7BDDB8; --c2:#1D9E75; --c3:#0F6E56; --glow: rgba(29,158,117,.5); }

.icon-3d.sm { width: 40px; height: 40px; border-radius: 15px; }
.icon-3d.sm.square {
  background:
    radial-gradient(circle at 32% 26%, rgba(255,255,255,.8), rgba(255,255,255,0) 40%),
    radial-gradient(circle at 35% 30%, var(--c1), var(--c2) 55%, var(--c3) 100%);
}

@keyframes pop {
  0% { transform: scale(1); }
  40% { transform: scale(1.22); }
  100% { transform: scale(1); }
}
.pop { animation: pop .35s ease; }

.theme-toggle {
  border: 1px solid var(--glass-border);
  background: var(--glass-surface);
  backdrop-filter: blur(var(--glass-blur)) saturate(160%);
  -webkit-backdrop-filter: blur(var(--glass-blur)) saturate(160%);
  color: var(--text-secondary);
  width: 38px; height: 38px;
  border-radius: 50%;
  cursor: pointer;
  display: inline-flex; align-items: center; justify-content: center;
  box-shadow: var(--glass-shadow), inset 0 1px 0 var(--glass-highlight);
  transition: transform .1s ease;
}
.theme-toggle:active { transform: scale(0.92); }

/* ---- goal progress ---- */
.goal-block {
  margin: 12px 0 4px; background: var(--glass-surface);
  backdrop-filter: blur(var(--glass-blur)) saturate(160%);
  -webkit-backdrop-filter: blur(var(--glass-blur)) saturate(160%);
  border: 1px solid var(--glass-border); border-radius: 22px;
  padding: 16px 18px; box-shadow: var(--glass-shadow), inset 0 1px 0 var(--glass-highlight);
}
.goal-label {
  display: flex; justify-content: space-between; align-items: center;
  font-size: 13px; color: var(--text-secondary); margin-bottom: 8px; font-weight: 600;
}
.goal-label strong { color: var(--text-primary); font-family: var(--font-display); font-size: 15px; }
.goal-bar {
  height: 10px; border-radius: var(--radius-pill);
  background: var(--purple-bg); overflow: hidden;
}
.goal-fill {
  height: 100%; border-radius: var(--radius-pill);
  background: linear-gradient(90deg, var(--purple), #A79FF0);
  box-shadow: inset 0 1px 0 rgba(255,255,255,.45);
  transition: width .4s ease;
}

/* ---- mock test ---- */
.mock-timer-bar {
  display: flex; align-items: center; justify-content: space-between;
  margin: 14px 0; gap: 10px;
}
.mock-timer {
  font-family: var(--font-display); font-weight: 800; font-size: 18px;
  padding: 7px 16px; border-radius: var(--radius-pill);
  background: var(--purple-bg); color: var(--purple);
  border: 1px solid var(--glass-border);
}
.mock-timer.low { background: var(--red-bg); color: var(--red-dark); animation: flicker 1.4s ease-in-out infinite; }
.mock-qcounter { font-size: 13px; color: var(--text-secondary); font-weight: 700; }
.mock-nav-row { display: flex; gap: 8px; margin-top: 14px; }
.mock-nav-row .btn { margin-top: 0; flex: 1; }
.mock-result-score {
  text-align: center; padding: 10px 0 4px;
}
.mock-result-score .big { font-family: var(--font-display); font-size: 40px; font-weight: 800; }
.mock-result-score .sub { color: var(--text-secondary); font-size: 13px; margin-top: 2px; }
.mock-topic-row {
  display: flex; align-items: center; justify-content: space-between;
  padding: 9px 0; border-top: 0.5px solid var(--border); font-size: 13.5px;
}
.mock-topic-row:first-of-type { border-top: none; }
.mock-topic-row .count { font-weight: 800; color: var(--text-secondary); }
.mock-review-item {
  background: var(--glass-surface);
  backdrop-filter: blur(var(--glass-blur)) saturate(160%);
  -webkit-backdrop-filter: blur(var(--glass-blur)) saturate(160%);
  border: 1px solid var(--glass-border); border-radius: 20px;
  padding: 14px; margin-top: 10px;
  box-shadow: var(--glass-shadow), inset 0 1px 0 var(--glass-highlight);
}
.mock-review-item .q-text { font-size: 13.5px; margin: 0 0 8px; font-weight: 600; }
.mock-review-item .answer-line { font-size: 12.5px; margin: 3px 0; }
.mock-review-item .answer-line.wrong { color: var(--red-dark); }
.mock-review-item .answer-line.right { color: var(--teal-dark); }
.mock-review-item .explanation { font-size: 12.5px; color: var(--text-secondary); margin-top: 6px; line-height: 1.5; }

/* ---- weak topics ---- */
.weak-topics-card {
  background: var(--glass-surface);
  backdrop-filter: blur(var(--glass-blur)) saturate(160%);
  -webkit-backdrop-filter: blur(var(--glass-blur)) saturate(160%);
  border: 1px solid var(--glass-border);
  border-radius: 22px; padding: 16px 18px; margin: 4px 0 20px;
  box-shadow: var(--glass-shadow), inset 0 1px 0 var(--glass-highlight);
}
.weak-topics-card h2 { font-size: 15px; margin: 0 0 4px; font-family: var(--font-display); }
.weak-topics-card .hint { font-size: 12.5px; color: var(--text-secondary); margin: 0 0 10px; line-height: 1.5; }
.weak-topic-row {
  display: flex; align-items: center; justify-content: space-between; gap: 10px;
  padding: 10px 0; border-top: 0.5px solid var(--border);
}
.weak-topic-row:first-of-type { border-top: none; padding-top: 4px; }
.weak-topic-name { font-weight: 700; font-size: 13.5px; }
.weak-topic-acc { font-size: 11.5px; color: var(--red-dark); font-weight: 800; display: block; margin-top: 1px; }
.weak-topic-practice {
  font-size: 12px; font-weight: 800; color: var(--purple); text-decoration: none;
  padding: 6px 12px; border-radius: var(--radius-pill); background: var(--purple-bg); white-space: nowrap;
}

/* ---- topic cards (home) ---- */
h1 { font-size: 23px; margin: 20px 0 4px; letter-spacing: -.01em; }
.subtitle { color: var(--text-secondary); font-size: 14px; margin: 0 0 16px; }

.topic-sections { display: block; }
.topic-grid { display: flex; flex-direction: column; gap: 10px; }

.section-heading {
  font-family: var(--font-display); font-size: 19px; font-weight: 700;
  margin: 26px 0 4px; padding-top: 16px; border-top: 0.5px solid var(--border);
}
.topic-sections > .section-heading:first-child,
#formula-sections > .section-heading:first-child { margin-top: 6px; padding-top: 0; border-top: none; }
.section-subheading {
  font-size: 11px; font-weight: 800; color: var(--text-muted);
  text-transform: uppercase; letter-spacing: .06em; margin: 12px 0 2px;
}
.topic-card {
  display: flex; flex-direction: column; gap: 8px;
  background: var(--glass-surface);
  backdrop-filter: blur(var(--glass-blur)) saturate(160%);
  -webkit-backdrop-filter: blur(var(--glass-blur)) saturate(160%);
  border: 1px solid var(--glass-border);
  border-radius: 20px; padding: 13px 15px 13px 13px;
  text-decoration: none; color: inherit;
  cursor: pointer;
  box-shadow: var(--glass-shadow), inset 0 1px 0 var(--glass-highlight);
  transition: transform .12s ease, box-shadow .12s ease, background .12s ease;
}
.topic-card:hover { box-shadow: 0 14px 34px rgba(40,35,70,.14), inset 0 1px 0 var(--glass-highlight); transform: translateY(-2px); background: var(--glass-surface-strong); }
.topic-card:active { transform: scale(0.98); }
.topic-card-row { display: flex; align-items: center; justify-content: space-between; gap: 12px; }
.topic-card-main { display: flex; align-items: center; gap: 12px; }
.topic-name { font-weight: 800; font-size: 15px; font-family: var(--font-display); }
.topic-meta { font-size: 12px; color: var(--text-muted); margin-top: 1px; font-weight: 600; }
.topic-arrow { color: var(--text-muted); flex: none; }
.topic-progress-track { height: 5px; background: var(--surface-2); border-radius: var(--radius-pill); overflow: hidden; }
.topic-progress-fill { height: 100%; background: linear-gradient(90deg, var(--teal), #4FC79A); border-radius: var(--radius-pill); transition: width .4s ease; }
.topic-today-badge {
  display: inline-flex; align-items: center; gap: 3px; align-self: flex-start;
  font-size: 10.5px; font-weight: 800; color: var(--text-muted);
  background: var(--surface-2); padding: 3px 8px; border-radius: var(--radius-pill);
}
.topic-today-badge.met { color: var(--teal-dark); background: var(--teal-bg); }
.topic-today-badge svg { flex: none; }

.mock-cta {
  margin-top: 24px; padding: 20px; border-radius: 24px;
  background: linear-gradient(135deg, var(--purple), #6a61cf);
  color: #fff;
  display: flex; align-items: center; justify-content: space-between;
  text-decoration: none; cursor: pointer; border: none; width: 100%;
  font: inherit; box-shadow: 0 10px 28px rgba(127,119,221,.45), inset 0 1px 0 rgba(255,255,255,.35);
}
.mock-cta strong { display: block; font-family: var(--font-display); font-size: 16px; }
.mock-cta span { font-size: 12px; opacity: 0.85; }
.mock-cta:disabled { opacity: .55; cursor: default; box-shadow: none; }

/* ---- practice screen ---- */
.progress-row { display: flex; align-items: center; gap: 8px; margin: 14px 0; }
.progress-track { flex: 1; height: 7px; background: var(--surface-2); border-radius: var(--radius-pill); overflow: hidden; }
.progress-fill { height: 100%; background: linear-gradient(90deg, var(--teal), #4FC79A); border-radius: var(--radius-pill); transition: width .3s ease; }
.progress-count { font-size: 12px; color: var(--text-muted); white-space: nowrap; font-weight: 700; }

.q-card {
  background: var(--glass-surface);
  backdrop-filter: blur(var(--glass-blur)) saturate(160%);
  -webkit-backdrop-filter: blur(var(--glass-blur)) saturate(160%);
  border: 1px solid var(--glass-border);
  border-radius: 26px; padding: 22px; margin-top: 8px;
  box-shadow: var(--glass-shadow), inset 0 1px 0 var(--glass-highlight);
  animation: card-in .25s ease;
}
@keyframes card-in {
  from { opacity: 0; transform: translateY(6px); }
  to { opacity: 1; transform: translateY(0); }
}

.tag-row { display: flex; gap: 6px; margin-bottom: 14px; flex-wrap: wrap; }
.tag {
  font-size: 11px; font-weight: 800; padding: 4px 11px;
  border-radius: var(--radius-pill); letter-spacing: .01em;
  background: var(--coral-bg); color: var(--coral-dark);
}
.tag.review { background: var(--amber-bg); color: var(--amber-dark); }
.tag.goal { background: var(--purple-bg); color: var(--purple); }
.tag.cat-level {
  background: linear-gradient(135deg, #2C2C2A, #54524A); color: #FFD98A;
  font-weight: 800; box-shadow: inset 0 1px 0 rgba(255,255,255,.12);
}
.tag.nmat-level {
  background: linear-gradient(135deg, #1B3A5C, #2F5C8A); color: #9FD3FF;
  font-weight: 800; box-shadow: inset 0 1px 0 rgba(255,255,255,.12);
}

.q-text { font-size: 17px; line-height: 1.55; margin: 0 0 18px; font-weight: 600; }

.group-panel {
  background: var(--surface-2); border-radius: 16px; padding: 14px 16px;
  margin-bottom: 14px; font-size: 13px; line-height: 1.6; color: var(--text-primary);
  white-space: pre-wrap; font-family: "SFMono-Regular", Consolas, monospace;
  border: 1px solid var(--border);
}
.group-panel-label {
  font-size: 11px; font-weight: 800; color: var(--text-muted);
  text-transform: uppercase; letter-spacing: .05em; margin-bottom: 6px;
  font-family: var(--font-body);
}

.options { display: flex; flex-direction: column; gap: 9px; }
.option-btn {
  display: flex; align-items: center; justify-content: space-between;
  border: 1.5px solid var(--glass-border); background: var(--glass-surface);
  backdrop-filter: blur(var(--glass-blur)) saturate(150%);
  -webkit-backdrop-filter: blur(var(--glass-blur)) saturate(150%);
  color: var(--text-primary);
  border-radius: 16px; padding: 13px 16px;
  font-size: 15px; font-weight: 700; text-align: left;
  cursor: pointer; font-family: var(--font-body);
  box-shadow: inset 0 1px 0 var(--glass-highlight);
}
.option-btn { transition: border-color .12s ease, transform .1s ease, background .12s ease; }
.option-btn:hover { border-color: var(--purple); }
.option-btn:active { transform: scale(0.98); }
.option-btn.selected { border-color: var(--purple); background: var(--purple-bg); }
.option-btn.correct { border-color: var(--teal); background: var(--teal-bg); color: var(--teal-dark); animation: pop .3s ease; }
.option-btn.incorrect { border-color: var(--red); background: var(--red-bg); color: var(--red-dark); }
.option-btn:disabled { cursor: default; }
.option-btn:disabled:hover { border-color: var(--glass-border); }
.option-btn.correct:disabled:hover, .option-btn.incorrect:disabled:hover { border-color: currentColor; }

.tita-row { display: flex; gap: 8px; }
.tita-row input {
  flex: 1; border: 1.5px solid var(--glass-border); border-radius: 16px;
  padding: 13px 16px; font-size: 15px; background: var(--glass-surface); color: var(--text-primary);
  backdrop-filter: blur(var(--glass-blur)) saturate(150%);
  -webkit-backdrop-filter: blur(var(--glass-blur)) saturate(150%);
  box-shadow: inset 0 1px 0 var(--glass-highlight);
  font-family: var(--font-body); font-weight: 700;
}
.tita-row input:focus { outline: none; border-color: var(--purple); }

.btn {
  border: none; border-radius: var(--radius-pill);
  padding: 14px 20px; font-size: 15px; font-weight: 800;
  cursor: pointer; font-family: var(--font-display);
  transition: transform .1s ease, box-shadow .1s ease;
  letter-spacing: .01em;
}
.btn:active { transform: scale(0.97); }
.btn-primary {
  background: linear-gradient(180deg, #8F87E8, var(--purple));
  color: #fff; width: 100%; margin-top: 16px;
  box-shadow: 0 6px 18px rgba(127,119,221,.42), inset 0 1px 0 rgba(255,255,255,.4);
}
.btn-primary:disabled { opacity: 0.5; cursor: default; box-shadow: none; }
.btn-ghost {
  background: var(--glass-surface); color: var(--text-secondary); border: 1.5px solid var(--glass-border);
  backdrop-filter: blur(var(--glass-blur)) saturate(150%);
  -webkit-backdrop-filter: blur(var(--glass-blur)) saturate(150%);
  box-shadow: inset 0 1px 0 var(--glass-highlight);
}

.feedback {
  margin-top: 16px; padding: 14px 16px; border-radius: 18px;
  font-size: 14px; line-height: 1.55;
  animation: card-in .25s ease;
  border: 1px solid transparent;
}
.feedback.correct { background: var(--teal-bg); color: var(--teal-dark); border-color: rgba(29,158,117,.25); }
.feedback.incorrect { background: var(--red-bg); color: var(--red-dark); border-color: rgba(226,75,74,.25); }
.feedback strong { font-family: var(--font-display); font-size: 15px; }
.feedback .xp-line { font-family: var(--font-display); font-weight: 800; margin-top: 8px; font-size: 15px; }

.flag-row { display: flex; gap: 8px; margin-top: 12px; }
.flag-btn {
  flex: 1; font-size: 12px; font-weight: 700; padding: 8px 10px; border-radius: var(--radius-pill);
  border: 1.5px solid var(--glass-border); background: var(--glass-surface); color: var(--text-secondary);
  cursor: pointer; font-family: var(--font-body);
  transition: transform .1s ease;
}
.flag-btn:active { transform: scale(0.96); }
.flag-btn:disabled { opacity: 0.7; cursor: default; }
.flag-btn.active-good { border-color: var(--teal); color: var(--teal-dark); background: var(--teal-bg); }
.flag-btn.active-bad { border-color: var(--red); color: var(--red-dark); background: var(--red-bg); }

.ai-ask { margin-top: 14px; }
.ai-ask-panel { margin-top: 10px; }
.ai-ask-input {
  width: 100%; border: 1.5px solid var(--glass-border); border-radius: 14px;
  padding: 10px 12px; font-size: 14px; background: var(--glass-surface); color: var(--text-primary);
  backdrop-filter: blur(var(--glass-blur)) saturate(150%);
  -webkit-backdrop-filter: blur(var(--glass-blur)) saturate(150%);
  font-family: var(--font-body); font-weight: 500; resize: vertical; min-height: 44px;
}
.ai-ask-input:focus { outline: none; border-color: var(--purple); }
.ai-ask-response {
  margin-top: 10px; padding: 12px 14px; border-radius: 16px;
  background: var(--purple-bg); color: var(--text-primary); font-size: 13.5px; line-height: 1.55;
  white-space: pre-wrap;
}
.ai-ask-response.loading { color: var(--text-muted); font-style: italic; }
.ai-ask-response.error { background: var(--red-bg); color: var(--red-dark); }

/* ---- in-practice calculator modal ---- */
.modal-backdrop {
  position: fixed; inset: 0; background: rgba(20,18,30,.38);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  display: flex; align-items: flex-end; justify-content: center;
  z-index: 50;
}
.modal-backdrop[hidden] { display: none; }
.calc-modal {
  width: 100%; max-width: 420px; border-radius: 26px 26px 0 0;
  margin: 0; max-height: 88vh; overflow-y: auto;
  padding-bottom: calc(18px + env(safe-area-inset-bottom, 0px));
  animation: card-in .22s ease;
}
.calc-modal-header {
  display: flex; align-items: center; justify-content: space-between;
  margin-bottom: 10px; font-family: var(--font-display); font-weight: 800; font-size: 15px;
}
.calc-modal-close {
  background: var(--surface-2); border: none; border-radius: 50%;
  width: 30px; height: 30px; font-size: 18px; line-height: 1; cursor: pointer; color: var(--text-secondary);
}

.back-link {
  display: inline-flex; align-items: center; gap: 4px; margin: 14px 0; color: var(--text-secondary);
  text-decoration: none; font-size: 13px; font-weight: 700;
}

.empty-state { text-align: center; color: var(--text-secondary); padding: 40px 0; font-weight: 600; }

/* ---- settings / generate panel ---- */
.settings-card {
  background: var(--glass-surface);
  backdrop-filter: blur(var(--glass-blur)) saturate(160%);
  -webkit-backdrop-filter: blur(var(--glass-blur)) saturate(160%);
  border: 1px solid var(--glass-border);
  border-radius: 22px; padding: 18px; margin-top: 14px;
  box-shadow: var(--glass-shadow), inset 0 1px 0 var(--glass-highlight);
}
.settings-card h2 { font-size: 16px; margin: 0 0 4px; }
.settings-card .hint { font-size: 12.5px; color: var(--text-secondary); margin: 0 0 14px; line-height: 1.55; }

.form-group { margin-bottom: 12px; }
.form-label { display: block; font-size: 12px; color: var(--text-secondary); margin-bottom: 4px; font-weight: 700; }
.form-input, .form-select {
  width: 100%; border: 1.5px solid var(--glass-border); border-radius: 14px;
  padding: 10px 12px; font-size: 14px; background: var(--glass-surface); color: var(--text-primary);
  backdrop-filter: blur(var(--glass-blur)) saturate(150%);
  -webkit-backdrop-filter: blur(var(--glass-blur)) saturate(150%);
  font-family: var(--font-body); font-weight: 600;
}
.form-input:focus, .form-select:focus { outline: none; border-color: var(--purple); }
.form-row { display: flex; gap: 8px; }
.form-row .form-group { flex: 1; }

.key-status { display: flex; align-items: center; gap: 8px; font-size: 12px; margin-top: 6px; font-weight: 700; }
.key-status.saved { color: var(--teal-dark); }
.key-status.missing { color: var(--text-muted); }

/* ---- auth / login ---- */
.auth-wrap { max-width: 380px; margin: 0 auto; padding-top: 8vh; }
.auth-tabs { display: flex; gap: 8px; margin-bottom: 16px; }
.auth-tab {
  flex: 1; padding: 10px; border-radius: 14px; border: 1.5px solid var(--glass-border);
  background: var(--glass-surface); color: var(--text-secondary); font-weight: 700;
  backdrop-filter: blur(var(--glass-blur)) saturate(150%);
  -webkit-backdrop-filter: blur(var(--glass-blur)) saturate(150%);
  font-size: 13px; cursor: pointer; font-family: var(--font-body);
}
.auth-tab.active { border-color: var(--purple); color: var(--purple); background: var(--purple-bg); }
.auth-hint { font-size: 12.5px; color: var(--text-secondary); margin: 0 0 14px; line-height: 1.55; }
.auth-error { color: var(--red); font-size: 13px; font-weight: 700; margin-top: 10px; }
.auth-remember {
  display: flex; align-items: center; gap: 8px; font-size: 13px;
  color: var(--text-secondary); font-weight: 600; margin: 2px 0 14px; cursor: pointer;
}
.auth-remember input { width: 16px; height: 16px; accent-color: var(--purple); }
.auth-remember[hidden] { display: none; }
.auth-link {
  display: block; width: 100%; text-align: center; background: none; border: none;
  color: var(--purple); font-size: 12.5px; font-weight: 700; font-family: var(--font-body);
  cursor: pointer; margin-top: 12px; padding: 4px;
}
.auth-link[hidden] { display: none; }

.gen-log { margin-top: 14px; display: flex; flex-direction: column; gap: 6px; max-height: 260px; overflow-y: auto; }
.gen-log-item {
  font-size: 12px; padding: 8px 10px; border-radius: 10px;
  background: var(--surface-2); line-height: 1.4;
}
.gen-log-item.ok { border-left: 3px solid var(--teal); }
.gen-log-item.review { border-left: 3px solid var(--amber); }
.gen-log-item.error { border-left: 3px solid var(--red); }

.gen-progress { font-size: 12px; color: var(--text-secondary); margin-top: 10px; font-weight: 700; }

/* ---- formula reference ---- */
.formula-search {
  width: 100%; border: 1.5px solid var(--glass-border); border-radius: var(--radius-pill);
  padding: 12px 18px; font-size: 15px; font-family: var(--font-body); font-weight: 600;
  background: var(--glass-surface); color: var(--text-primary); margin: 14px 0 4px;
  backdrop-filter: blur(var(--glass-blur)) saturate(150%);
  -webkit-backdrop-filter: blur(var(--glass-blur)) saturate(150%);
  box-shadow: inset 0 1px 0 var(--glass-highlight);
}
.formula-search:focus { outline: none; border-color: var(--purple); }

.formula-grid { display: grid; grid-template-columns: 1fr; gap: 14px; margin-top: 16px; }

.formula-card {
  background: var(--glass-surface);
  backdrop-filter: blur(var(--glass-blur)) saturate(160%);
  -webkit-backdrop-filter: blur(var(--glass-blur)) saturate(160%);
  border: 1px solid var(--glass-border);
  border-radius: 22px; padding: 16px 18px;
  box-shadow: var(--glass-shadow), inset 0 1px 0 var(--glass-highlight);
}
.formula-card-head { display: flex; align-items: center; gap: 10px; margin-bottom: 10px; }
.formula-card-head h3 { margin: 0; font-size: 16px; }

.formula-item { padding: 9px 0; border-top: 0.5px solid var(--border); }
.formula-item:first-of-type { border-top: none; padding-top: 2px; }
.formula-label { font-size: 12.5px; font-weight: 800; color: var(--text-secondary); margin-bottom: 2px; }
.formula-expr {
  font-family: "SFMono-Regular", Consolas, monospace; font-size: 13.5px;
  color: var(--text-primary); line-height: 1.5;
}
.hidden { display: none !important; }

/* ==================================================================
   Motion: idle life, entrances, celebration
   ================================================================== */

/* streak flame flickers gently -- never fully still */
@keyframes flicker {
  0%, 100% { transform: scale(1) rotate(0deg); }
  25% { transform: scale(1.05) rotate(-2deg); }
  50% { transform: scale(0.97) rotate(1deg); }
  75% { transform: scale(1.03) rotate(2deg); }
}
.icon-3d.flame { animation: flicker 2.6s ease-in-out infinite; }

/* topic cards + option buttons stagger in on load */
@keyframes rise-in {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}
.topic-card, .option-btn { animation: rise-in .38s cubic-bezier(.2,.8,.3,1.2) backwards; }

/* bouncier button press than a flat scale */
.btn:active, .option-btn:active, .theme-toggle:active, .flag-btn:active {
  transition: transform .08s cubic-bezier(.34,1.56,.64,1);
}

/* number pop used by animateNumber() whenever a stat changes */
@keyframes number-bump {
  0% { transform: scale(1); }
  30% { transform: scale(1.35); }
  60% { transform: scale(0.95); }
  100% { transform: scale(1); }
}
.number-bump { display: inline-block; animation: number-bump .4s cubic-bezier(.34,1.56,.64,1); }

/* confetti particle -- position/color/travel set inline per-piece by JS */
.confetti-piece {
  position: fixed; top: 0; left: 0; width: 8px; height: 8px;
  border-radius: 2px; pointer-events: none; z-index: 999;
  opacity: 1;
  animation: confetti-fly .9s cubic-bezier(.15,.7,.3,1) forwards;
}
@keyframes confetti-fly {
  0% { transform: translate(var(--x0), var(--y0)) rotate(0deg) scale(1); opacity: 1; }
  100% { transform: translate(var(--x1), var(--y1)) rotate(var(--spin)) scale(.4); opacity: 0; }
}

/* goal-complete celebration toast */
.celebrate-toast {
  position: fixed; left: 50%; top: 16px; transform: translateX(-50%) translateY(-30px);
  background: linear-gradient(135deg, var(--purple), #6a61cf); color: #fff;
  padding: 12px 20px; border-radius: var(--radius-pill);
  font-family: var(--font-display); font-weight: 700; font-size: 14px;
  box-shadow: 0 10px 28px rgba(127,119,221,.5), inset 0 1px 0 rgba(255,255,255,.4);
  display: flex; align-items: center; gap: 8px;
  z-index: 1000; opacity: 0;
  animation: toast-in .45s cubic-bezier(.2,.8,.3,1.2) forwards, toast-out .4s ease 2.6s forwards;
}
@keyframes toast-in { to { opacity: 1; transform: translateX(-50%) translateY(0); } }
@keyframes toast-out { to { opacity: 0; transform: translateX(-50%) translateY(-20px); } }

/* skeleton loading shimmer, replaces plain "Loading..." text */
.skeleton {
  background: linear-gradient(90deg, var(--surface-2) 25%, var(--border) 37%, var(--surface-2) 63%);
  background-size: 400% 100%;
  animation: shimmer 1.4s ease infinite;
  border-radius: 16px;
}
@keyframes shimmer { 0% { background-position: 100% 0; } 100% { background-position: 0 0; } }
.skeleton-card { height: 58px; margin-bottom: 10px; }
.skeleton-line { height: 14px; margin-bottom: 8px; }

@media (prefers-reduced-motion: reduce) {
  .icon-3d.flame, .topic-card, .option-btn, .confetti-piece, .celebrate-toast, .skeleton {
    animation: none !important;
  }
}

/* ---- mixed practice / weak-topics / profile accents share the glass look
   via the rules above; nothing extra needed here ---- */

/* ---- calculator ---- */
.calc-card {
  background: var(--glass-surface);
  backdrop-filter: blur(var(--glass-blur)) saturate(160%);
  -webkit-backdrop-filter: blur(var(--glass-blur)) saturate(160%);
  border: 1px solid var(--glass-border);
  border-radius: 26px; padding: 16px; margin-top: 14px;
  box-shadow: var(--glass-shadow), inset 0 1px 0 var(--glass-highlight);
}

.calc-display {
  position: relative; background: var(--surface-2); border-radius: 18px;
  padding: 18px 16px 14px; margin-bottom: 12px; text-align: right;
  border: 1px solid var(--border);
}
.calc-mem-badge {
  position: absolute; top: 10px; left: 14px;
  font-family: var(--font-display); font-size: 12px; font-weight: 800;
  color: var(--purple-dark); background: var(--purple-bg);
  padding: 2px 8px; border-radius: var(--radius-pill);
}
.calc-expr {
  font-size: 14px; color: var(--text-secondary); font-weight: 600;
  min-height: 18px; word-break: break-all; font-family: "SFMono-Regular", Consolas, monospace;
}
.calc-result {
  font-family: var(--font-display); font-size: 32px; font-weight: 700;
  margin-top: 4px; word-break: break-all;
}

.calc-grid { display: grid; gap: 8px; margin-bottom: 8px; }
.calc-grid-5 { grid-template-columns: repeat(5, 1fr); }
.calc-grid-4 { grid-template-columns: repeat(4, 1fr); }

.calc-btn {
  border: 1px solid var(--glass-border); border-radius: 14px; background: var(--glass-surface);
  backdrop-filter: blur(var(--glass-blur)) saturate(150%);
  -webkit-backdrop-filter: blur(var(--glass-blur)) saturate(150%);
  color: var(--text-primary); font-family: var(--font-body); font-weight: 700;
  font-size: 14px; padding: 12px 4px; cursor: pointer;
  box-shadow: inset 0 1px 0 var(--glass-highlight);
  transition: transform .08s cubic-bezier(.34,1.56,.64,1), background .1s ease;
}
.calc-btn:active { transform: scale(0.93); background: var(--border); }
.calc-btn.calc-op { background: var(--purple-bg); color: var(--purple-dark); font-size: 16px; }
.calc-btn.calc-toggle { background: var(--teal-bg); color: var(--teal-dark); font-size: 12px; }
.calc-btn.calc-toggle.calc-btn-active { background: var(--teal); color: #fff; }
.calc-btn.calc-mem { background: var(--amber-bg); color: var(--amber-dark); font-size: 12px; }
.calc-btn.calc-clear-btn { background: var(--red-bg); color: var(--red-dark); }
.calc-btn.calc-back-btn { background: var(--red-bg); color: var(--red-dark); font-size: 16px; }
.calc-btn.calc-equals {
  background: linear-gradient(180deg, #8F87E8, var(--purple)); color: #fff;
  font-size: 18px; box-shadow: 0 4px 14px rgba(127,119,221,.45), inset 0 1px 0 rgba(255,255,255,.4);
}
.calc-btn.calc-fn { font-size: 12.5px; }

/* ==================================================================
   Responsive breakpoints -- placed last so they win the cascade over
   the single-column base rules above, instead of losing to them.
   ================================================================== */
@media (min-width: 700px) {
  .wrap { max-width: 900px; padding: 0 32px; }
  .topic-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 12px; }
  .q-card, .settings-card { max-width: 640px; margin-left: auto; margin-right: auto; }
  .calc-card { max-width: 400px; margin-left: auto; margin-right: auto; }
  .formula-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (min-width: 1000px) {
  .wrap { max-width: 1080px; }
  .topic-grid { grid-template-columns: repeat(3, 1fr); }
  .formula-grid { grid-template-columns: repeat(3, 1fr); }
}